That code is obviously a vacuum leak and the mechanics cannot find it. Maybe you can find it yourself? Do a good visual and then start the car up until warm, spray parts cleaner/carb cleaner around the intake and vacuum hoses liberally and listen or "feel" for the engine RPM changing, then you pinpointed the vacuum leak.
I used to work at a dealer and it seems their inability to solve a simple problem and blame it on another product that has nothing to do with the PCM other than monitoring systems has created more problems than it solved.
Good luck my friend
